A habit calendar that lives inside my notes

I used to track habits on a whiteboard calendar, marking an X on every day I worked on a side project. When I needed the whiteboard for something else I moved to printed calendars taped to the wall. Seeing months of progress stacked up next to each other was super gratifying.
I wanted that back this year, but I didn't want another app to sign into. I'm already spread across too many of them.
I do open Obsidian every single day though. So I built a habit calendar that embeds directly into my notes. It sits in my daily note, I click a day to mark it done, and I can go back and fill in previous days without digging through old files. The existing Obsidian plugins I tried store habit data inside each daily note, which is what made backfilling annoying, so mine keeps the data in its own database and renders the calendar on top.
The code is public on GitHub, and I wrote about the habits I'm actually tracking in New year, new habits.